Ch. 6 Ct Exam And Anatomy Part. 1 Flashcards
Indications Ct exam of the head p 7
Trauma, stroke, headache, tumors, endocrine disease, inflammatory disease, and congenital problems
Ct exam head _____ slices always required p 7
Transverse
Ct exam of head requires coronal and sagital slices for p 7
Internal auditory canals, temporal bones , pituitary, orbits, sinuses and facial bones
Ct of head patient enter gantry p 7
Head first supine
Two ways obtaining coronal images of head p 7
Patient supine and head first Hyperextended patien head and top gantry tilted 20 degrees
Patient prone and head first resting on chin and gantry tilted back 20 degrees
Localizer of head ct is what image? P 7
Lateral
Iv contrast for head ct administered ? P 8
Highlight vascular structures of the brain to indicate a disruption of the blood brain barrier
Ct exam of brain patient entered gantry p 9
Head first and supine
Contrast media not admixtures for exam of brain p9
Cerebral trauma
Suspected atrophy
Hydrocephalus
Dementia
Contrast administered for ct of brain p 9
Tumors Abscesses Edema Aneurysm Headaches and seizures
Axial slices of brain acquired from the ______ to _____. P 9
Skull base
Vertex
Typical brain slice thickness reconstruction p 9
5mm slices
Why thinner slices on ct of brain? P 9
Reduce streaks scanning through posterior fossa and pretrous ridges
Routine brain scan technique p 10
300 ma kvp 120
Bone window level of head p 11
Width: 2500
Level - 350
Posterior fossa window width and level p 11
Width: 200
Level: 40
Soft tissue of head window width and level p 11
Width: 100
Level: 30
Ct posterior fossa scan ( skull base) p 16
Head first supine scan
Axial slices only
From foramen magnum through the tentorium
Posterior fossa scan no contrast medium p 16
Cerebral trauma
Suspected atrophy
Hydrocephalus
Dementia
Posterior fossa scan contrast administered p 16
Tumors Abscesses Edema Aneurysms Headaches Seizures
Posterior fossa scan slice thickness p 16
1.5-5mm
Mas for posterior fossa scan p17
300-400 mas
Posterior fossa bone detail ww/wl
2500 ww and 350 wl
Posterior fossa soft tissue window p 16
Ww 160 and wl 40
I nternal auditory canal / temporal bones contrast exam p 18
Hearing loss to,rule out acoustic neuroma and malignant Ottis externa
I nternal auditory canal / temporal bones without contrast p 18
Depict temporal bone , mastoiditis, and cholestatoma
Instructions for study of I nternal auditory canal / temporal bones p 18
No swallowing
Slices thickness of I nternal auditory canal / temporal bones
0.5-2mm
I nternal auditory canal / temporal bones exam covers from? P 18
1cm inferior external auditory canal and superiorly petrous bone
Mas used for I nternal auditory canal / temporal bones p 19
200-400 mas
I nternal auditory canal / temporal bones technique
200-400 mas
I nternal auditory canal / temporal bones standard filter vs sharp filter p 19
Standard - soft tissue
Sharp - High resolution
I nternal auditory canal / temporal bones soft tissue window p 20
Ww- 200, wl- 50
I nternal auditory canal / temporal bones sharp algorithmn p 20
Ww- 2500
wl-300
Pituitary exam p 22
Head first and supine
Both axial and coronal
Contrast always administered
Pituitary exam _____ provide more information because _____ exam causes streak artifacts from dense bone of sella turcica
Coronal
Axial
Pituitary slice thickness p 22
0.5-2mm
Pituitary axial slices show p 22
Roof of sphenoid sinus through dorsum sella
Pituitary Coronal slices show p 22
Anterior clinoid process to dorsum sella
Pituitary exam mas p 23
200-400 mas
Pituitary soft tissue ww/wl p22
Ww-200
Wl-50
Pituitary sharp algorithmn ww/wl p 23
Ww-2500
Wl- 300
Orbit exam p 24
Axial and coronal images acquired
Head first and supine
Patient instructed to focus eyes on one thing or close them
No contrast media orbit exam p 24
Trauma, foreign bodies, Graves’ disease
Contrast for orbit exam p 25
Suspected mass in or around eye , visual disturbances, evaluating infection
Orbit exam slice thickness p 24
2mm or less
Axial images of orbits from p 24
Top maxillary sinus to upper orbital rim
Coronal slices orbit exam p 24
Sphenoid sinus to anterior globe
_______ images of orbits best demonstrate the relationship between the lens and intraorbital optic nerve
Transverse
Orbit exam mas p 26
200
Orbit soft tissue ww/wl p 26
Ww-200
Wl- 50
Orbit sharp algorithmn p 26
Ww- 2500
Wl- 300
Sinuses exam p 29
Both axial and coronal slices
Head first and supine
Contrast for sinuses p 29
Suspected mass such as lymphoma or inverted papilloma
No contrast for sinus exam p 29
Sinusitis
Sinus exam slices p 29
3 mm or less
Sinus axial exam from p 29
Hard palate through superior aspect frontal sinus
Coronal slices for sinus exam p
Dorsum sella to anterior aspect of frontal sinuses
Sinus exam mas p 30
200 mas
Sinus soft tissue p 30
Ww- 250
Wl- 50
Sharp algorithmn sinus p 31
Ww- 2000
Wl- 300
Facial bone exam p 34
Axial or coronal slices
Supine and head first
Why no contrast facial bone exam ? P 34
Head trauma